This notebook has Intel 82801CA/CAM AC'97 card according to lspci. I've
read some article about how to configure the soundcard. Some says it
works with oss driver (i810_audio), some says it only works with alsa
(intel8x0). I've tried both, but the end was the same. The modules
loaded successfully but I can't hear any sound.
According to Red Hat articles sndconfig can set it. So I installed
sndconfig and tried it. It detected the rigth card, loaded the modules,
but no sound.

Just check that the sound channels aren't muted. I think they are by
default, which caught me out.

Fire up alsamixer and check. press 'm' to mute/unmute. "MM" appears at
the top of the sliders, and "[Off]" appears in the "Item" header.